JP2003067284A - Digital broadcast receiver - Google Patents

Abstract

(57) [Summary] [Problem] To make it easy for a user to judge whether or not a version upgrade is required by displaying items that improve a problem that has actually occurred when confirming whether or not to upgrade the version. . When an error occurs internally in a program, a means for specifying the location and state of the error, a means for comparing an improvement in the transmitted program with an error internally generated, If the result of the comparison is that there is a means for notifying the user that a new program can be improved if they match, and a means for upgrading if the user chooses to upgrade to the new program, an error has occurred Sometimes, if a new program has already been received, it is configured so that it can be immediately replaced with an improved program.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital broadcast receiver, and more particularly to a download / upgrade method for receiving and rewriting a program transmitted by broadcast waves.

[0002]

2. Description of the Related Art Digital broadcasting such as CS and BS realizes multi-channel and high-quality broadcasting by using MPEG2 and digital modulation technology which are international standards for compression and transmission of video and audio. is there.

In digital broadcasting, a broadcasting station converts a video, audio, program information, additional data, etc. of a program into a compressed and encoded data sequence (hereinafter referred to as a stream), and then a plurality of streams called a transport stream. A new single stream is created by multiplexing the above-mentioned streams of the program, digitally modulated and transmitted. On the other hand, on the receiver side, the reverse operation to that on the broadcasting station side, that is, after digital demodulation by the tuner, the multiple programs multiplexed in the transport stream are separated, and only the desired program is extracted, and the video, Decompresses and decodes audio, program information, and additional data, and displays them on the TV screen.

FIG. 1 shows an example of the configuration of a digital broadcast receiver. In FIG. 1, 1 is a remote controller, 2 is a tuner for demodulating received radio waves, 3 is each video, audio, program information, additional data, etc. of each program for which the transport stream multiplexed and designated is specified. Separation circuit for separating signals (hereinafter referred to as DEMUX), 4 is D
An audio decoder for decompressing and decoding the digital audio data separated by EMUX3, a video decoder 5 for expanding and decoding the digital MPEG video data separated by DEMUX3, and 6 for displaying contents such as menus and additional data On-screen display (OSD) device, 7 is an interface (I / F) such as a remote control light receiving unit, and 8 is a rewritable non-volatile memory for holding broadcast data and receiver-specific data even when the power is off. (Hereinafter referred to as NVRAM), 9
Is a microprocessor (hereinafter referred to as CPU) that controls the overall operation of the digital broadcast receiver, and 10 functions as a work memory for operating a program during operation of the digital broadcast receiver, and stores various data. A RAM (hereinafter referred to as a work memory) for storing and reading, 11 is a program memory for storing a program for operating the CPU 9, and 12 is a modem.

The operation of the digital broadcast receiver will be described below. The CPU 9 controls the entire system.
The program 9 is stored in the program memory 11. The NVRAM 8 is a rewritable non-volatile memory and is used for holding data in a power-off state. For example, it stores data such as temporary storage of program information, program reservation information set by the user, and antenna setting state that need to be retained even when the power is turned off.

The received signal is demodulated by the tuner 2. The demodulated transport stream signal is D
The EMUX 3 separates a stream of video, audio, program information, additional data, etc., and supplies it to each block. The video stream is decoded by the video decoder 5, combined with a menu or the like by the OSD device 6, and output as a video signal. The audio stream is decoded by the audio decoder 4 and output as an analog audio signal.
Further, the program information is stored in the work memory 10 and converted into data such as a program table by the CPU 9 as necessary,
It is combined with the video signal by the OSD device 6 and displayed on the screen as an electronic program guide.

Further, the function of the digital broadcast receiver can be changed by changing the program of the CPU 9 incorporated therein, so that the function is changed in accordance with the change of the broadcast standard and the performance / function of the receiver is improved. In addition, in order to correct defects in the program and the like, a method of downloading a new program for operating the CPU 9 through a broadcast wave is adopted. The program to be downloaded is multiplexed and sent together with streams of video, audio, program information, additional data, and the like. On the receiver side, the program must be separated and extracted from the broadcast wave and stored in the program memory 11.

Next, the configuration of the download compatible receiver will be described. In FIG. 1, the download program data transmitted after being mixed with the broadcast wave is separated by the DEMUX 3 by the same method as the program information and stored in the work memory 10.

Regarding the conventional download thereafter, FIG.
Will be explained. 2 is the CPU of FIG. 1 which has already been described.
9 is a diagram in which a portion including 9, NVRAM 8, and program memory 11 is extracted, and is a configuration example in the case of being compatible with download.

In FIG. 2, 11a is a program memory (A) of the program memory 11, 11b is a program memory (B) of the program memory 11, and 21 is an instruction of the CPU 9 to control each part by an address bus and a data bus. A system bus for performing the operation, 22 is a selector switch for switching between the program memory (A) 11a and the program memory (B) 11b.

The system bus 25 is connected to other parts such as the DEMUX 3. The CPU 9 has a program memory (A) 11a and a program memory (B) 11b.
It has one program memory, and one of them is used as an effective program memory to actually operate, and the other is used to store the download program data.
If download is completed normally, selector switch 2
The downloaded program can be used by switching the valid program memory in 2.

At the time of downloading, the CPU 9 causes the DEM
The download data is read from the UX3 into the work memory 10 and written in the program memory (B) 11b. When the download is completed normally, the selector switch 2 is activated so that the program memory (B) 11b becomes valid.
2 is switched, and the user is informed of the content such as "Download is completed" on the screen display. Then, next, the program memory (B) 11b becomes an effective program memory, and the program memory (A)
11a is for downloading.

Next, a conventional download processing flow will be described below with reference to the flowchart of FIG.

First, a schedule for receiving program data is received (step S31). This schedule contains information such as which channel, from when and how long it will be sent, as well as information about which receiver is the target.When the schedule of the corresponding receiver is received, the download A series of processing is started. Normally, when the download schedule is received, the receiver user can select whether to automatically execute the download. If (YES in step S32), the download is automatically executed without confirming whether to execute the download, and if the automatic execution is not selected (manual execution is selected) ( In the case of NO at step S32), a confirmation message such as "I have notification of download. Do you want to download?" Is displayed (step S33). Then, if "not execute" is selected in step S34 (NO in step S34), the process is terminated without executing download. On the other hand, if "execute" is selected in step S34 (YES in step S34), preparation for download processing is started.

In this way, when the download is to be executed, the schedule management is performed according to the received schedule when the download is executed (step S3).
5). Then, the designated channel is selected at the time determined there, and the reception of the program data is started (step S36). The data is written in the program data storage area while being received in some cases (step S3
7). If all the program data is received and the program data is normal, the program is switched to the received program (step S38). Finally, a message such as "Download completed normally" is displayed (step S3).
9) The download process ends.

[0016]

Conventionally, downloading has not always been compulsorily performed by the user.
You can choose to do or not. Therefore, it may not be downloaded unless the user has a clear advantage. Further, although the display of points that are usually improved is displayed, the display may be stopped without actually looking at the display. In addition, if the period is short, the chances of failing to download will increase. Therefore, the period is usually set with a margin. However, there is a natural cost involved in downloading, so the longer the download period, the higher the cost. In addition, even if the period is set with some margin, the user often does not download during that period. Then, after the end of the period, the user may request a version upgrade. For example, a user downloads to fix a certain defect, but the user has never encountered the defect and either did not download it, or thought that the download should be performed later, but forgot it. is there. However, after that, the user may request a version upgrade even if a problem is encountered after the download period ends. In such a case, the service will be called, a service person will be dispatched, and the version will be upgraded directly, and in some cases large costs may be incurred.

Therefore, in the present invention, in order to minimize the cost, it is easy for the user to select the version upgrade of the software (program) in the case of actual failure, and even if the download period is short, or The purpose of the present invention is to provide a digital broadcast receiver that realizes this so that service personnel do not have to be dispatched even after the download period ends.

[0018]

In order to achieve the above object, a digital broadcast receiver for receiving a digital broadcast in which a video signal, an audio signal, and at least program data are multiplexed and transmitted as encoded digital data. , Means for separating the video signal, the audio signal, and the program data from the received signal and storing the program data, and means for specifying the location and state of the program when an error internally occurs, and transmitted. It is equipped with a means to check what is improved in the program and the one in which an error has occurred internally, and if there is a match as a result of checking, means to notify the user that the new program will be improved and it is sent. Identify where and when the program can improve and where and when the program makes an internal error Immediately improve if the new program is already received when the error occurs, by identifying and matching them and notifying the user that the new program will improve if they match. Be replaced by a program.

Further, when the program to be transmitted is received, by comparing the error that has occurred in the past with the error that can be dealt with by the download, it is possible to determine whether or not the item actually improved at the time of download. The notification may facilitate the user to select whether or not to upgrade.

Further, a means for storing the program data in a place different from the previous program data, a means for allowing the user to select a method for automatically switching the stored program and a method for manually switching the stored program, and a new method for storing the stored program It has a means to switch as a program,
If the user manually selects the switching method and the user does not switch to the new program, the user may be allowed to switch to the new program even after the download period is short and the program data has been transmitted.

On the contrary, it is also possible to switch to the old program so that even if there is something wrong with the new program, it can be returned to the previous program.

Further, the program data may be recorded in a plurality of places, and not only selection of new or old, but selection of what is new or old may be selected.

When the program data is stored in the flash memory, the compressed data is stored in the flash memory, and the compressed data is expanded and executed on the RAM at the time of startup, thereby saving the capacity of the flash memory and reducing the cost. You may do it.

If a hard disk is provided,
A hard disk usually has a large capacity, and the unit price per capacity is much cheaper than flash memory.
By storing the program data in a part of the hard disk and expanding and executing it on the RAM, the capacity of the flash memory for storing the normal program data is saved,
The cost may be reduced.

If an external storage card is provided,
By storing the program data in the external storage card so that the program stored in the external storage card can be written to the receiver, the program of the digital broadcast receiver that cannot receive the program can be replaced with the other digital broadcast receiver. Alternatively, the program may be rewritten to the program recorded in the external recording card.

[0026]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. The basic configuration of the digital broadcast receiver according to the embodiment of the present invention is the same as the configuration of FIG. 1 described above, and includes a CPU 9, data related to download / upgrade control stored in the NVRAM 8, and a work memory 10. Arithmetic / control means such as each specifying, collating, and switching means in the claims of the present application is embodied by the downloaded program and data related to the download control.

FIG. 8 is a data example of an error occurrence content and an improved error used in the embodiment of the present invention. The error occurrence content 81 stores the situation when the receiver detects an internal error. Error condition "1" 8
2. The error condition “2” 83 is an error condition added to the program data sent by download and improved and upgraded, and the content of the error. The error occurrence content 81, the error condition “1” 82, and the error condition “2” 83 are stored in an appropriate memory area of the receiver.

Next, an example of version upgrade processing for performing error collation according to an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to the flowchart of. In this example, the processing flow is started when an error occurs in the receiver.

First, when an error occurs in the receiver (step S91), the error occurrence content 8 as shown in FIG.
1 is stored (step S92). Next, it is checked whether or not there is already a new program for version upgrade in the program memory 11 (step S9).
3) If there is no new program for version upgrade (NO in step S93), the process ends.

If a new program for version upgrade already exists (YES in step S93), the error condition of the error improved by the upgraded program is compared with the error content generated in the receiver. (Step S94) Then, it is checked whether the error generated in the receiver is an error that can be improved by performing the version upgrade (step S95). For example, in the case of the error condition “1” 82 in FIG. 8, the error ID
The setting state and the error location are compared with the error occurrence content 81, and if the error occurrence content meets the error condition, it is determined that the error is improved. If it is determined that the error is not improved by performing the version upgrade (NO in step S95), the process ends.

When it is determined that the error is improved by performing the version upgrade (Y in step S95).
If it is ES), a message is displayed to confirm whether or not to upgrade (step S96),
It is determined whether the user has selected the upgrade (step S97), and if the user has not selected the upgrade (NO in step S97),
The process ends. If the user selects the version upgrade (YES in step S97), the program is immediately switched (step S98),
Upgrade the version. Then, finally, notification (display) that the version upgrade has been normally completed is performed (step S99), and the process is terminated.

Further, regarding another example of the version upgrade processing for performing error collation according to the embodiment of the present invention,
This will be described with reference to the flowchart of FIG. In this example,
The processing flow is started when the receiver receives the download schedule.

First, a schedule for receiving the program data is received, and when the schedule of the receiver is received, the download process is started (step S101). Next, according to the received schedule, schedule management is performed when it is executed (preferably, when the user is not using the receiver) (step S102). Next, the designated channel is selected at the time determined in step S102, the program data is received (step S103), and the program memory is received via the work memory 10 while receiving the program data in some cases. The data is written in the program data storage area such as 11 (step S104). When all the program data are received and the program data is normal, the program storing process is completed here.

Next, in step S105, when the download schedule is received, it is determined whether or not it is set to automatically perform the version upgrade (the user separately sets the download schedule in advance). When receiving, I have selected whether to automatically perform the version upgrade, and check the setting status). In the case where the user does not select the automatic execution of the program version upgrade (the setting in which manual execution is selected) (in the case of NO in step S105), the error content that occurred in the receiver in the past, The received program is automatically downloaded and collated with the error condition of the error improved by the new program (step S10).
6). Next, a display that shows how the error that occurred in the receiver is improved and a display that prompts you to select whether to upgrade the program (for example, "There is a notification that the receiver control software has been upgraded. Do you want to execute? ”Is displayed) (step S107). Next, it is determined whether the user has selected the version upgrade (step S
108). If the user has not selected the upgrade (NO in step S108), the process ends.

If the upgrade is selected in step S108 (YES in step S108) and if the automatic execution of program upgrade is selected (YES in step S105), immediately. , Switch to a new program that has been received and stored, and perform the version upgrade (step S109), and finally notify (display) that the version upgrade has completed normally (step S110), and end the processing. To do.

Further, regarding an example of the version upgrade process without error collation according to the embodiment of the present invention,
This will be described with reference to the flowchart of FIG. In this example, the processing flow is started when the receiver receives the download schedule.

First, a schedule for receiving the program data is received, and when the schedule of the receiver is received, the download process is started (step S41). Next, according to the received schedule, schedule management is performed when it is executed (preferably, when the user is not using the receiver) (step S42). Next, the designated channel is selected at the time determined in step S42, and the program data is received (step S43).
In some cases, while receiving, it writes in the program data storage area (step S44). If all program data is received and the program data is normal,
Here, the process of storing the program is completed.

Next, in step S45, when the download schedule is received, it is determined whether or not it is set to automatically execute the version upgrade. If the user does not select the automatic execution of the program version upgrade (the setting in which manual execution is selected) (in the case of NO in step S45), the message "Upgrade notification of receiver control software There is ... A confirmation message such as "Do you want to upgrade?" Is displayed (step S46). Next, it is determined whether or not the user has selected the version upgrade (step S47). If the user does not select the version upgrade (NO in step S47), the process ends.

When the upgrade is selected in step S47 (YES in step S47) and the setting is such that automatic execution of the program upgrade is selected (YES in step S45)
Immediately switches to the new program that it has received and stored and upgrades (step S
48) Finally, notification (display) that the version upgrade has been completed normally is given (step S49), and the process ends.

In the processing flows of FIGS. 10 and 4, if NO is determined in step S108 or step S47, the processing ends without upgrading the version, but the processing flows of FIGS. After the end of
Since we have already received and stored the new program,
You can upgrade the version simply by switching the program later. Therefore, in one embodiment of the present invention, for example, the user performs an appropriate key operation on the remote controller 1 or the like to instruct a version upgrade, or confirms whether or not to upgrade again at some timing. It is possible to perform a version upgrade by instructing the version upgrade at. This is the same even after the NO determination is made in step S97 in the processing flow of FIG.

In addition, in one embodiment of the present invention, even after the completion of the version upgrade, the previous program is stored (only erased) until the program data is rewritten next. Then, when the user has a problem by changing to the latest program, for example, and has a request to return to the previous program, the user performs an appropriate key operation on the remote controller 1 or the like to return to the old program. You can switch to the old program by instructing that.

Next, a first modification of the embodiment of the present invention will be described with reference to FIG. In this example, a plurality of programs are stored in the flash memory.

In FIG. 5, reference numeral 51 is a flash memory having a program memory (A) 51a, a program memory (B) 51b, ..., A program memory (N) 51n and functioning as a program memory.

When storing a program, the program memory (A) 51a, the program memory (B) 51b,
.., program memory (N) 51n, and so on. And, if you always upgrade to the latest version, you can arbitrarily switch the program to the previous program or the previous program by instructing how many old ones to switch It is like this. Also, if you have not upgraded the version, by instructing how many new ones to switch to, one program newer than the current one,
It is possible to arbitrarily switch to subsequent programs including the latest program, and by instructing how many old programs to switch, the program can be switched to the previous program or the previous program arbitrarily. It is possible to switch.

Normally, the program is stored in the flash memory 51 as the execution data as it is and is executed on the flash memory 51. However, as shown in FIG. 5, the flash memory 51 stores the program in a RAM (work memory).
A program loader 51-1 to be loaded into the memory 10 may be stored in advance, the program may be loaded into the RAM 10 from a program memory that executes the program at the time of startup, and the program may be executed on the RAM 10. In this case, it is not necessary to store the program data as the execution data in the flash memory 51, and the program data can be compressed. That is, it is possible to save the costly memory resources of the flash memory by compressing and storing the program data at the time of storage and restoring it at the time of loading.

Next, a second modification of the embodiment of the present invention will be described with reference to FIG. In this example, a part of the hard disk is used as a program memory to store a plurality of programs on the hard disk.

In FIG. 6, reference numeral 61 is a hard disk having a program memory (A) 61a, a program memory (B) 61b, ..., A program memory (N) 61n, a partial area of which is a program memory, and 62 is a hard disk. An I / F (interface) that controls input / output between the receiver 61 and each unit (system bus 21) of the receiver.

The CPU 9 is a RAM (work memory) 1
0, the flash memory 51 is accessed via the system bus 66, and the hard disk 61 is accessed via the system bus 21 and the I / F 62.

When downloading, the program data is stored in the program memory (A) of the hard disk 61.
61a, program memory (B) 61b, ..., Program memory (N) 61n, in that order, are stored as compressed or uncompressed. In addition, a program loader 51-1 for loading a program in the RAM 10 is separately stored in the flash memory 51. If the program loader 51-1 does not need to be rewritten, a read only memory (ROM) may be used instead of the flash memory. Then, the program executed by the program loader 51-1 at the time of startup is stored in the hard disk 61
To RAM 10 and execute the program on RAM 10.

As a result, the costly flash memory can be kept to a minimum size, or
It becomes possible to replace the flash memory with a cheaper ROM. Note that, also in this example, switching to an arbitrary program is the same as in the first modified example.

Next, a third modification of the embodiment of the present invention will be described with reference to FIG. In this example, as shown in FIG. 7, an external storage card 71 can be attached to the receiver.

The CPU 9 accesses the RAM 10 and the flash memory 51 via the system bus 21, and accesses the external storage card 71 via the system bus 21 and I / F 62.

When downloading, the program data is not only stored in the flash memory 51, but also written in the external storage card 71. If there is a program stored in the internal memory or the external storage device in another receiver, the program data is read into the external storage card 71 from the other receiver by some operation, and then the external storage card 71 is read. It is also possible to load the program into the receiver for which the program is to be downloaded, write the program data of the external storage card 71 into the flash memory 51, and finally switch the program.

By adopting such a configuration, even when the program cannot be downloaded because the power plug of the receiver is unplugged during the download period, the program is rewritten via the external storage card 51. It becomes possible.

[0055]

As described above, according to the present invention, when confirming whether or not to upgrade, whether or not the problem actually occurred is displayed is displayed, so that the necessity of the upgrade by the user is displayed. It is possible to make a selection decision in consideration of the merits and effects, which makes it possible for receiver manufacturers to reduce the cost of downloading digital broadcast programs. Also, it is possible to reduce the cost of the digital broadcast receiver.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a digital broadcast receiver.

FIG. 2 is a block diagram of a main part of a digital broadcast receiver.

FIG. 3 is a flowchart showing a download processing flow according to a conventional technique.

FIG. 4 is a flowchart showing an example of a process flow of version upgrade without error verification according to an embodiment of the present invention.

FIG. 5 is a block diagram of a main part of a digital broadcast receiver according to a first modified example of the embodiment of the present invention.

FIG. 6 is a block diagram of a main part of a digital broadcast receiver according to a second modification of the embodiment of the present invention.

FIG. 7 is a block diagram of a main part of a digital broadcast receiver according to a third modified example of the embodiment of the present invention.

FIG. 8 is an explanatory diagram showing an error occurrence content used in the embodiment of the present invention and a data example of an improved error.

FIG. 9 is a flowchart showing an example of a process flow of version upgrade for performing error collation according to the embodiment of the present invention.

FIG. 10 is a flowchart showing another example of the process flow of version upgrade for error checking according to the embodiment of the present invention.

[Description of Codes] 1 remote control 2 tuner 3 separation circuit (DEMUX) 4 audio decoder 5 video decoder 6 on-screen display (OSD) device 7 interface 8 non-volatile memory (NVRAM) 9 microprocessor (CPU) 10 RAM (work memory) 11 Program Memory 11a Program Memory (A) 11b Program Memory (B) 12 Modem 21 System Bus 22 Selector Switch 51 Flash Memory 51a to 51n Program Memory (A) to Program Memory (N) 51-1 Program Loader 61 Hard Disk 61a to 61n Program memory (A) to program memory (N) 62 I / F (interface) 71 External storage card

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H04N 5/44 H04N 7/08 Z 7/08 G06F 9/06 640A 7/081 F term (reference) 5B076 AC01 AC03 AC07 BB04 BB06 5C025 BA27 CA09 CB10 DA01 5C063 AA01 AB03 AB07 AC01 AC05 CA11 CA36 5K028 AA01 BB04 CC05 DD01 DD02 EE03 EE05 EE08 KK03 QQ00 SS24 5K061 BB06 JJ06 JJ07

Claims (8)

[Claims] 1. A digital broadcast in which a video signal, an audio signal, and at least program data are multiplexed as encoded digital data, and a video signal, an audio signal, and program data are separated from the received signal, Means for storing program data, means for locating the location and state of an internal error when the program has an error, and collation of what is improved in the transmitted program and what has an error internally Means for notifying the user that the new program will be improved in the case of a match as a result of the collation, and means for upgrading the version if the user chooses to upgrade to the new program, If you have already received a new program when the error occurred Digital broadcasting receiver, wherein which can be replaced with the ram. 2. The method according to claim 1, further comprising means for collating what is improved in the program to be transmitted and one in which an internal error has occurred in the past, and as a result of collation, the error that occurred in the past is a new program. It is equipped with a means to notify the user that it will be improved, and at the time of download, by notifying whether it actually occurred in the item to be improved, making it easier for the user to select whether to upgrade A digital broadcast receiver characterized in that 3. The method according to claim 1, wherein the program data is stored in a place different from the previous program data, and the new program is automatically stored during the download period regardless of the user's intention. And a means for allowing the user to select a method for automatically switching the stored program or a method for manually switching the stored program, and a means for switching the stored program as a new program. A digital broadcast receiver characterized in that it allows the user to switch to a new program even after the program data has been sent out due to a short download period when the program is not switched to a new program. 4. The new program according to claim 1, further comprising means for storing an old program until a new program is stored, and means for switching to the old program. Even if there is a problem, the digital broadcast receiver is characterized in that it can return to the previous program. 5. The method according to any one of claims 1 to 4, further comprising means (location) for recording a plurality of program data, and not only selection of new or old, but how many new or how old A digital broadcast receiver characterized in that it can be selected as a designated item. 6. The program data according to claim 1, wherein the program data is stored in a flash memory,
In the flash memory, means for storing compressed data,
A digital broadcast receiver characterized by comprising means for expanding and executing it on a RAM at the time of startup, saving the capacity of the flash memory and reducing the cost. 7. The device according to claim 1, further comprising a hard disk if the hard disk is provided, and a means for storing the program data in a part of the hard disk.
A digital broadcast receiver characterized by comprising means for expanding and executing the above, to save the capacity of a flash memory for storing normal program data and to reduce the cost. 8. The external storage card according to claim 1, further comprising means for storing program data in the external storage card and a receiver for storing the program data in the external storage card. The digital broadcast receiver is characterized in that the program of another digital broadcast receiver that cannot receive the program can be rewritten.